1. Field of the Invention
The present invention relates to a range image generation apparatus, a position and orientation measurement apparatus, a range image processing apparatus, a method of controlling the range image generation apparatus, and a storage medium. The present invention particularly relates to a range image generation apparatus which generates range data of a target measurement object and performs image processing based on the range data, a position and orientation measurement apparatus, a range image processing apparatus, a method of controlling the range image generation apparatus, and a storage medium.
2. Description of the Related Art
In a three-dimensional range-measurement method using triangulation, when the measurement-point density is always constant, the in-plane resolution of range data decreases as the distance to the target measurement object increases. To perform measurement always at a predetermined in-plane resolution independently of the distance to the target measurement object, it is necessary to change the measurement-point density in accordance with the distance to the target measurement object.
As a method of changing the measurement-point density in accordance with the distance up to the target measurement object, a method as disclosed in Japanese Patent Laid-Open No. 2002-22425 has been examined.
In Japanese Patent Laid-Open No. 2002-22425, the distance up to the target measurement object is coarsely measured by light-propagation time measurement (TOF). Then, slit light is scanned by a light-section method in accordance with a scanning pitch determined based on the distance, thereby generating range data. In this case, the scanning pitch corresponds to the measurement-point density.
In the method of Japanese Patent Laid-Open No. 2002-22425, range data is generated based on the course range to the target measurement object. However, no consideration has been made about how to cope with a change in the in-plane resolution or depth-direction range resolving power requested for the generated range data in processing using the range data.
Generating range data having an in-plane resolution or depth-direction range resolving power higher than the requested resolution or range resolving power leads to an increase in the processing time due to the generation of unnecessary data. Conversely, generating range data having an in-plane resolution or depth-direction range resolving power lower than the requested resolution or range resolving power makes it difficult to maintain the accuracy of processing using the range data.
The present invention has been made in consideration of the above-described problems, and provides a technique of generating range data having the accuracy necessary for image processing in consideration of the in-plane resolution or depth-direction range resolving power requested by the processing using the range data.